乖
guāi · HSK 7
well-behaved
🐶 guāi sounds like why so good? — what you ask an obedient, well-behaved kid
The same character splits two ways: its old sense is to diverge or oppose (be at variance), but today it mostly means obedient and well-behaved, said of a calm child or a good pet.
乖 — 千 (thousand) on top + 北 (north) split below
乖 originally depicted something split or divided down the middle, with the upper element over a divided form resembling 北. Its earliest sense was 'to go against, deviate, be contrary.' Over time it shifted in colloquial Chinese to describe a child who is well-behaved — obedient enough not to stray — which is now its most common meaning.